CASE 16034 Published on 11.10.2018

Teaching Case

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Leenknegt B, Zebari S, Rufai O, Kibriya N, Sidhu PS.

Department of Radiology, King's College Hospital, Denmark Hill, London, United Kingdom. Email: benjamin.leenknegt@ugent.be

Patient

34 years, female

Categories

Area of Interest Liver ; Imaging Technique Catheter arteriography, Ultrasound, Ultrasound-Colour Doppler, CT ;

Procedure Diagnostic procedure, Contrast agent-intravenous ; Special Focus Aneurysms, Cysts ;

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Clinical History

A 34-year old woman with a transplant liver 3 years previously for Wilson’s disease was referred for an ultrasound (US) examination of the liver, for monitoring of abnormal liver function tests and work-up for re-transplantation. The patient had undergone a trans-jugular liver biopsy 10 days before, with no complications recorded.

Differential Diagnosis List

Angiography confirmed the diagnosis of pseudoaneurysm of the hepatic artery.

Simple hepatic cyst

Hepatic abcess

Imaging Findings

A B-mode US (Fig. 1) demonstrated an intrahepatic anechoic area, close to the portal vein. A colour Doppler US (Fig. 2) depicted turbulent flow within the anechoic area with the “ying-yang” appearance of a pseudoaneurysm. Contrast-enhanced ultrasound (CEUS) (Fig. 3-4) demonstrated the feeding hepatic artery branch. The pseudoaneurysm drained into the adjacent hepatic vein. A biphasic contrast-enhanced CT (Fig. 5) shows a 4.1 x 2.2 cm bi-lobulated intrahepatic lesion. The CEUS features were confirmed, and a pseudoaneurysm arising from the liver biopsy likely. Angiography was performed to proceed to coil embolization (Fig. 6). The pseudoaneurysm, arising from the right hepatic artery, was not embolized; because of a risk of ischaemia due to the proximal position of the pseudoaneurysm, the tortuosity of the feeding artery and the prominent drainage into the hepatic vein. In addition, re-transplantation was scheduled, and occurred 10 days following the detection of the pseudoaneurysm.

Discussion

Hepatic artery pseudoaneurysm (HAP) is a rare vascular complication of liver transplantation [1-5], with a reported incidence between 0.27–3 % [2, 3, 5]. HAP is classified according to location as intrahepatic or extrahepatic, with a different pathogenesis [2, 4, 6]. Intrahepatic HAP is most commonly related to an interventional procedures such as liver biopsy, percutaneous trans-hepatic cholangiography or trans-hepatic biliary drainage [4, 6] and is often an incidental finding on surveillance US [2, 3]. Extra-hepatic pseudo-aneurysm are most frequently secondary to an infectious aetiology. This can be systemic haematogenous spread or local sepsis following a biliary leak, breakdown of the Roux-en-Y hepatico-jejunostomy or a small bowel perforation [2, 4, 6]. Rupture of HAP - with consequent haemobilia or intraperitoneal hemorrhage - has a high mortality rate [2, 5, 7]. B-mode US and colour Doppler US are the first-line imaging modality to evaluate vascular complications in the post-transplant liver [1, 2, 4]. On US the HAP appears as a pulsatile anechoic area of varying size close to the hepatic artery, often abutting the vessel [1, 2, 8]. Colour Doppler US depicts the typical “ying-yang” pattern. Spectral Doppler US can show a turbulent, bidirectional or - in rare cases - slow monophasic flow [1, 2, 8, 9]. Contrast-enhanced ultrasound has been used to assess vascular complications following liver transplantation [8, 10-12]. CEUS can depict a HAP as a circular area of contrast perfusion in the hepatic arterial phase [8, 13]. Angiography is the reference standard for diagnosis and treatment planning of vascular complications post-liver transplant [2, 7]. It should be performed in cases of suspected HAP with negative imaging findings [2]. In case of rupture, coil embolization can be used emergently to achieve hemostasis in hemodynamically unstable patients [7]. Using super-selective embolization techniques, graft ischemia resulting from hepatic artery occlusion sometimes can be avoided. In cases of a ruptured HAP involving the anastomosis or main hepatic artery, occlusion of the inflow – which renders the graft ischaemic – can be used as a temporary measure pending emergency re- transplantation. If no bleeding is present, a decision regarding intervention depends on the likely outcome of acute ischemia, the status of the graft and feasibility of revascularization or re-transplantation [2]. In selected cases (i.e. a narrow neck of the HAP), stent graft placement with balloon angioplasty can be a therapeutic option [14].

Written informed patient consent for publication has been obtained.

References

[1] Girometti R, Como G, Bazzocchi M, Zuiani C. (2014) Post-operative imaging in liver transplantation: state-of-the-art and future perspectives. World journal of gastroenterology 20(20):6180-200. (PMID: 24876739)

[2] Marshall MM, Muiesan P, Srinivasan P, Kane PA, Rela M, Heaton ND, Karani JB, Sidhu PS. (2001) Hepatic artery pseudoaneurysms following liver transplantation: incidence, presenting features and management. Clin Radiol 56(7):579-87. (PMID: 11446757)

[3] Parlak S, Gulcek S, Kaplanoglu H, Altin L, Deveer M, Pasaoglu L. (2015) Hepatic Artery Pseudoaneurysm: A Life-Threatening Complication of Liver Transplantation. J Belg Soc Radiol 99(2):61-4. (PMID: 30039109)

[4] Singh AK, Nachiappan AC, Verma HA, Uppot RN, Blake MA, Saini S, Boland GW. (2010) Postoperative imaging in liver transplantation: what radiologists should know. Radiographics 30(2):339-51. (PMID: 20228321)

[5] Volpin E, Pessaux P, Sauvanet A, Sibert A, Kianmanesh R, Durand F, Belghiti J, Sommacale D. (2014) Preservation of the arterial vascularisation after hepatic artery pseudoaneurysm following orthotopic liver transplantation: long-term results. Ann Transplant 19:346-52. (PMID: 25034853)

[6] Kim HJ, Kim KW, Kim AY, Kim TK, Byun JH, Won HJ, Shin YM, Kim PN, Ha HK, Lee SG, Lee MG. (2005) Hepatic artery pseudoaneurysms in adult living-donor liver transplantation: efficacy of CT and Doppler sonography. AJR Am J Roentgenol 184(5):1549-55. (PMID: 15855114)

[7] Chen J, Weinstein J, Black S, Spain J, Brady PS, Dowell JD. (2014) Surgical and endovascular treatment of hepatic arterial complications following liver transplant. Clin Transplant 28(12):1305-12. (PMID: 25091402)

[8] Sidhu PS, Marshall MM, Ryan SM, Ellis SM. (2000) Clinical use of Levovist, an ultrasound contrast agent, in the imaging of liver transplantation: assessment of the pre- and post-transplant patient. Eur Radiol 10(7):1114-26. (PMID: 11003407)

[9] Elsayes KM, Shaaban AM, Rothan SM, Javadi S, Madrazo BL, Castillo RP, Casillas VJ, Menias CO. (2017) A Comprehensive Approach to Hepatic Vascular Disease. Radiographics 37(3):813-836. (PMID: 28430541)

[10] Berry JD, Sidhu PS. (2004) Microbubble contrast-enhanced ultrasound in liver transplantation. Eur Radiol 14 Suppl 8:P96-103. (PMID: 15700337)

[11] Sidhu PS, Ellis SM, Karani JB, Ryan SM. (2002) Hepatic artery stenosis following liver transplantation: significance of the tardus parvus waveform and the role of microbubble contrast media in the detection of a focal stenosis. Clin Radiol 57(9):789-99. (PMID: 12384104)

[12] Sidhu PS, Shaw AS, Ellis SM, Karani JB, Ryan SM. (2004) Microbubble ultrasound contrast in the assessment of hepatic artery patency following liver transplantation: role in reducing frequency of hepatic artery arteriography. Eur Radiol 14(1):21-30. (PMID: 14530998)

[13] Ren X, Luo Y, Gao N, Niu H, Tang J. (2016) Common ultrasound and contrast-enhanced ultrasonography in the diagnosis of hepatic artery pseudoaneurysm after liver transplantation. Exp Ther Med 12(2):1029-33. (PMID: 27446316)

[14] Lu NN, Huang Q, Wang JF, Wei BJ, Gao K, Zhai RY. (2012) Treatment of post-liver transplant hepatic artery pseudoaneurysm with balloon angioplasty after failed stent graft placement. Clin Res Hepatol Gastroenterol 36(6):e109-13. (PMID: 22766148)

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